Toggle switch

ABSTRACT

A toggle switch comprises a housing with a toggle switch mechanism therein located on one side of a transverse wall structure of the housing. The switch mechanism includes a sector pivotally mounted on the housing and carrying a movable contact for engagement with fixed contacts in the housing. The sector has a surrounding skirt that slides on the transverse wall structure whereby the fixed and movable contacts are substantially enclosed. The plastic material forming the enclosure is of a noninflammable type having a high resistance to arcing. A groove between the fixed contacts increases the arc path resulting from surface buildup of conductive material removed from the contacts due to the arcing.

United States Patent Baumanis Mar. 26, 1974 TOGGLE SWITCH Primary Examiner-Roy N. Envall, Jr.

Attorney, Agent, or Firm-Olson, Trenler, Wolters, [75] Inventor. Bruno Baumanls, R1ver Forest, Ill. Bushnell & Posse Ltd- [73] Assignee: Molex Incorporated, Lisle, Ill.

[22] Filed: Feb. 12, 1973 [57] ABSTRACT [21] Appl' 33l776 A toggle switch comprises a housing with a toggle switch mechanism therein located on one side of a [52] US. Cl 200/67 C transverse wall structure of the housing. The switch [51 Int. Cl. H0lh 5/14, HOlh 21/08 mechanism includes a sector pivotally mounted on the i ld Of ar /63 63 6 A, 67 C, housing and carrying a movable contact for engage- 200/ 168 G, 144 B ment with fixed contacts in the housing. The sector has a surrounding skirt that slides on the transverse References Cited wall structure whereby the fixed and movable contacts UNITED STATES PATENTS are substantially enclosed. The plastic material form- 3,440,37s 4/1969 Baird 200/147 B mg the enclosure is of non'inflammable WW having 3,366,755 1/1968 Kl'ehbiel zoo/67c a high resistance areing- A groove between the 3,015,706 1/1962 Fichter 200/67 c fixed Contacts increases the are P resulting from 2,820,864 1/l958 Newman et al. 200/67 C surface buildup of conductive material removed from 2,524,784 10/1950 Franks et al. 200/67 C the contacts due to the arcing. 2,131,590 9/1938 Hathorn ZOO/67 C 7 Claims, 9 Drawing Figures TOGGLE SWITCH BACKGROUND OF THE INVENTION This invention relates to improvements in snapaction or toggle switches.

Various types of snap-action mechanisms are commonly used to interrupt and complete electrical circuits for phonographs, television sets, and related equipment. Switches of this type must be capable of making and breaking the electrical circuit quickly, and for this reason the movable contact of the switch is driven into and out of engagement with the fixed contacts in a positive and forceful manner. In addition to the positive action required of the switch, the latter should be of a relatively inexpensive construction so that mass production costs are held to a minimum. It is known that switches of this type produce arcing when making or breaking contacts, the arcing being most pronounced during contact breaking. It is also recognized that contact arcing may constitute a fire hazard, and for this reason recently upgraded standards of safety have required that the switch contacts be enclosed in a high-grade, non-inflammable material.

Another problem with switches of this type lies in the fact that contact arcing tends to blow off conductive material, which results in a surface buildup of conductive material between the fixed contacts. In due time the surface build up may shorten the arc gap between the fixed contacts to the point where arc over will take place and the switch will be short-circuited.

OBJECTS AND SUMMARY OF THE INVENTION An object of this invention is to provide a toggle switch of relatively simple and inexpensive construction and wherein the switch contacts are substantially completely enclosed by a non-inflammable, high-grade plastic material, whereby the hazard of fire is reduced and modern safety standards are met.

A further object of this invention is to provide a toggle switch of the type stated which can be used for various types of equipment and is of a design suitable for installation in many types of presently existing equipment.

A still further object of this invention is to provide a toggle switch of the type stated wherein the plate or wall that forms part of the substantially enclosed chamber has grooves, between the fixed contacts, that collects blown off particles due to arcing. Because the surface of the groove tends to collect these particles, the arc path between the fixed contacts is lengthened.

In accordance with the foregoing objects the switch comprises a housing having longitudinal and transverse dimensions, a transverse wall structure on the housing, and a switch mechanism on the housing on one side of the transverse wall structure and including a switch sector pivotally mounted on the housing. Connector pins are fixed to the housing and extend from the transverse wall structure longitudinally in the opposite direction from the sector. The connector pins also have portions extending through the transverse wall structure toward the sector and with those portions carrying fixed switch contacts. An actuator arm is pivotally mounted on the housing and cooperates with a spring connected to the actuator arm and to the sector to form a toggle linkage. A movable contact is carried by the sector and engages the fixed contacts when the sector is toggled to a first position and is separated from the fixed contacts when the sector is toggled to a second position. The sector has a wall spaced from the transverse wall structure and a skirt projecting from the sector wall toward the transverse wall structure and surrounding the fixed and movable contacts. The skirt is in sliding engagement with the transverse wall structure, whereby the sector cooperates with -the transverse wall structure to form a substantially imperforate enclosure for the fixed and movable cont'acts.

Yet another object of this invention is to provide a toggle switch of the type stated in which the transverse wall structure is formed by adjacent wall sections in face-to-face engagement, and with the wall section that constitutes part of the enclosure for the switch contact being of a material having a higher resistance to arcing than the other wall section. As a result, the principle portion of the housing can be made of a relatively less expensive plastic as compared to the plastic used for the first mentioned wall section and the switch sector. In addition the less expensive plastic has a desired degree of flexibility that aids in flexing of the mounting prongs of the housing for installation purposes.

Still another object of this invention is to provide a toggle switch of the type stated in which the movable contacts may be a cup-shaped element that is confined between the first-mentioned wall section and the sector, and loosely receives an oval-shaped projection on the sector whereby the cup-shaped element floats to some extent and is readily positioned for clean contact making and breaking with the fixed contacts.

Still another object of this invention is to provide a toggle switch of the type stated that utilizes, as an alternative embodiment, a U-shaped movable contact that is retained and carried by the sector.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a perspective view of a toggle switch constructed in accordance with and embodying the present invention;

FIG. 2 is a partial exploded perspective view of the structure of FIG. 1;

FIG. 3 is a top plan view of the structure of FIG. 1 and shows the switch in its actuated or contact-making position;

FIG. 4 is a fragmentary sectional view, on an enlarged scale, taken along line 44 of FIG. 2;

FIG. 5 is a top plan view similar to FIG. 3 but showing the switch in its non-operating position, namely with the movable contact out of engagement with the fixed contacts;

FIG. 6 is a fragmentary sectional view, on an enlarged scale, taken along line 6-6 of FIG. 5;

FIG. 7 is a sectional view taken along line 77 of FIG. 5 and showing the switch housing secured to a part of a mounting panel or casing that forms part of the equipment with which the switch is used;

FIG. 8 is a fragmentary top plan view of a modified form of switch in accordance with this invention; and

FIG. 9 is a fragmentary sectional view, on an enlarged scale taken along line 9-9 of FIG. 8.

DETAILED DESCRIPTION Referring now in more detail to the drawing, which illustrates a preferred embodiment of the present invention, there is shown a switch 2 comprising a housing 4 having a housing wall that is formed by a generally semi-cylindrical section 6, a section 8 of lesser height, and a section 10 of a height the same as that of section 6. Between the sections 6 and 10 there is a gap 12. Integral with and extending axially from the end of the wall sections 6, 10 are prongs 14 that have tapered entering surfaces, as shown. These prongs serve to mount the switch housing 4 on a suitable supporting surface 16 (FIG. 7) that forms part of the equipment with which the switch is used. The entire switch housing 4, including the integral prongs 14, are of a resilient plastic material. This may be any known type of moldable plastic having sufficient resiliency whereby the prongs 14 can flex during installation through respective openings 18 in the member 16. By way of example but not of limitation, the housing may be formed of a suitable polycarbonate resin.

The housing 4 also includes a tubular socket 20 that is integrally joined to the wall sections 6, 8, 10 by a transverse wall section 22 (FIG. 7). Also integrally extending from the transverse wall section 22 at the periphery thereof and in the gap 12 is a cylindrical boss 24. Staked to the transverse wall section 22 are spaced apart, parallel pins 26, 28, 30, which project into the socket 20 for connection to a companion plug or for connection to other terminal devices forming part of the circuit in which the switch is located.

In the embodiment illustrated, the connector pin 26 is not operatively connected to the switch mechanism, but may be used with auxiliary equipment. As will be seen hereafter, the connector pins 28, 30 have fixed switch contacts for selective connection to a movable contact that is actuated by a toggle mechanism. Suffice it to say for the present, however, that the pins 26, 28, 30 extend in the axial or longitudinal direction of the housing and away from the wall section 22. In addition, the wall section 22 has an aperture for receiving a ground pin 32 (FIG. 7) that may connect to the plug with which the socket 20 is used.

Mounted in flush relationship with the wall section 22 is another transverse wall section 34. The transverse wall sections 22, 34 constitute a transverse wall structure on the housing 4. The wall sections 22, 34 may be held together in any suitable manner. In the present embodiment of the invention, the plastic of the wall section 22 is molded with integral upstanding fingers 36, 36 (FIGS. 2 and 4) while the wall section 34 is molded with holes 38, 38 (one being shown in FIG. 4) for respectively receiving fingers 36, 36 when the wall sections 22, 34 are assembled. Thus, upon such assembly of the wall section 22, 34 the fingers 36, 36 are each momentarily heated to form on each a head 40 of enlarged diameter, whereby the wall sections 22, 34 are clinched together. To accommodate each head 40, the upper surface of the wall section 34 is molded with a recess 42 that is in line with and is of larger diameter than the associated hole 38.

Pivotally mounted on the housing 4 is a member or switch sector 44 that is a one-piece plastic member having an end or transverse wall 46 and a peripheral skirt 48 that is generally perpendicular to the transverse wall section 34 and is in sliding contact therewith. The sector 44 also integrally includes a sleeve 50 that receives the boss 24 and by which the sector 44 is pivotally connected to the housing 4. Furthermore, and as best seen in FIG. 7, the part of the sleeve 50 that spans the space between the end wall 46 and the transverse wall section 34 constitutes a part of the skirt 48. Therefore, the sector 44 and the transverse wall section 34 cooperate to form a substantially imperforate enclosure having a chamber 52.

As previously pointed out, the connector pins 26, 28, 30 are staked to the wall section 22. However. these connector pins also extend through the wall section 34 in a direction toward the sector 44. The pins 28, 30 are provided, at the portions thereof within the chamber 52, with switch contacts 54, 56. It will be noted from FIG. 7 that the pins 26, 28, 30 project through the wall section 34 with some clearance. This clearance precludes fully sealing the chamber 52 in the strictest sense by the wall section 34. However, the clearances are comparatively small with the result that the wall section 34 is substantially imperforate at least to the extent necessary to enclose the switch contacts for purposes of the present invention.

Also pivotally mounted on the boss 24 at the upper end thereof and adjacent to the sleeve 50 is an actuator arm 58. The actuator arm 58 is bifurcated at one end so that a suitable actuating member may be inserted between the two arms 60, 62 for purposes of operating the switch. sleeve 50 and the actuator arm 58 are held in assembled relationship with the boss 24 by a headed pin 64 that is pressed into the bore of the boss 24 as most clearly seen in FIG. 7. The switch mechanism also includes a hairpin spring 66 having opposed, angularly related arms 68, 70. The arm 70 is hooked into a hole 72 at one end of the actuator arm 58 while the arm 68 is inserted into a blind hole 74 in the end wall 46 of the sector 44. For this purpose the sector wall 46 may be thickened to provide a hole 74 of proper length and yet not perforate the wall 46.

Positioned within the chamber 52 is a movable contact 76 that is carried into and out of engagement with the fixed contact 54, 56 by movement of the sector 44. For this purpose the sector wall 46 integrally includes a depending projection 78 that is loosely received in the bore or recess 80 of the movable contact 76, as best seen in FIG. 6. The movable contact 76 may be an annular member, for example in the form of a cup having a base metal of brass 82 that is clad with a thin layer of silver 84. The annular movable contact 76 may also be simply a ring-shaped member rather than the cup-shaped member shown.

The switch is in the non-actuated or open condition when the parts are in the positions shown in FIG. 5. When the actuator arm 58 is rotated counterclockwise to the position shown in FIG. 3, the switch sector 44 will rotate clockwise in a snap-action manner under force of the spring 66 when the actuator arm 58 toggles past dead center. This brings the movable contact 76 into engagement with the fixed contacts 54, 56. When the actuator arm 58 is rotated clockwise from the position shown in FIG. 3 to that shown in FIG. 5, movement past dead center toggles the sector 44 back to the position shown in FIG. 5 to open the switch.

Since the projection 78 is smaller than the recess 80, the movable contact 76 is mounted in a floating manner. Furthermore, as seen in FIGS. 3 and 5, the projection 78 is somewhat oval shaped which tends to form a ridge or point 86 (FIG. 5) at the part of the projection 78 that is presented toward fixed contacts 54, 56. Tis point 86 tends to engage the contact 76 and carry it toward the contacts 54, 56 when the mechanism is toggled to the switch-on position shown in FIG. 3. Also the contact 76 is permitted a certain amount of lateral play relative to its direction of motion. The result is that the contact 76 can rock about point 86 for proper selfcentering between the fixed contacts 54, 56.

The sector 44 and the wall section 34 are each molded of a non-inflammable material that has a high resistance to arcing. Such a material may be a phenolic resin or other resin having the desired properties. Materials of this type are commercially available. In any event, the sector 44 and wall section 34 cooperate to enclose the fixed and movable contacts of the switch in a manner to reduce the possibility of fire hazard from arcing of the switch contacts. However, the plastic material forming the balance of the housing need not have the arc and flame resistant properties of the sector 44 and the wall section 34, whereby the cost of the switch is reduced.

FIGS. 8 and 9 show a switch with enclosed contacts and of the type previously described, except that the movable contact is of U-shaped configuration. Thus, the movable contact 90 has opposed resilient arms 92, 94 which tend to expand outwardly. At the bight of the contact 90 is an angled portion 96 having an aperture therein for receiving a rivet 98. This rivet 98 is imperforate and passes through the sector wall 46. The inside of the sector wall 46 is formed with a groove 100 for receiving the contact 90 whereby the arms 92, 94 are pressed toward one another in opposition to their normal tendency to spring apart. When the contact 90 is in the groove 100, the spacing between the arms 92, 94 is greater than the distance between the fixed contacts 54, 56. When the switch mechanism is toggled to the closed position from the open position shown in FIG. 8, the arms 92, 94 will be urged toward each other by the fixed contacts 54, 56. However, the spring forces of the arms 92, 94 will make effective wiping contact with the fixed contact.

Regardless of the type of movable contact used, it will be noted from FlGS. 2 and 7 that the transverse wall section 34 is formed with a groove 102 that is approximately mid-way between the fixed contacts 54, 56 and opens toward the chamber 52. The line generally between the fixed contacts is perpendicular to the groove 102. Tis groove This the arc path between the fixed contacts 54, 56 resulting from a surface buildup of conductive material that is removed from the contacts due to arcing. ln the absence of the groove 102, the buildup would have a shorter path directly between the fixed contacts. Accordingly, the provision of the groove 102 is likely to lengthen the service life of the switch.

The invention is claimed as follows:

1. A switch comprising a housing having longitudinal and transverse dimensions, a transverse wall structure on said housing, a switch mechanism in said housing on one side of said transverse wall structure and including a switch sector pivotally mounted on said housing-connector pins fixed to said housing and extending from said transverse wall structure longitudinally in the opposite direction from said sector, said connector pins also having portions extending through said transverse wall structure toward said sector and with said portions having fixed switch contacts, an actuator arm pivotally mounted on said housing, spring means connecting said sector and said actuator arm in a manner to form a toggle linkage, a movable contact carrried by said sector and engaging said fixed contacts when the sector is toggled to a first position and being separated from said fixed contacts when the sector is toggled to a second position, said sector having a wall spaced from said transverse wall structure and a skirt projecting from the sector wall toward said transverse wall structure, said skirt surrounding said fixed and said movable contacts and being in sliding engagement with said transverse wall structure, said sector thereby cooperating with said transverse wall structure to form substantially an imperforate enclosure for the fixed and movable contacts.

2. A switch according to claim 1 in which said transverse wall structure includes two adjacent wall sections in surface-to-surface engagement.

3. A switch according to claim 1 in which said wall structure has a groove running between the fixed contacts.

4. A switch according to claim 2 in which one of said wall sections is engaged by said skirt, said one wall section and said sector being of a material having a higher resistance to arcing than the other wall section.

5. A switch according to claim 1 in which said movable contact is an annular element and a projection is integral with said sector for loosely receiving said element.

6. A switch according to claim 5 in which said projection is oval shaped at the part that is received by said element.

7. A switch according to claim 1 in which said movable contact has opposed arms for respective engagement with said fixed contacts, and said sector is internally grooved for receiving said movable contact. 

1. A switch comprising a housing having longitudinal and transverse dimensions, a transverse wall structure on said housing, a switch mechanism in said housing on one side of said transverse wall structure and including a switch sector pivotally mounted on said housing, connector pins fixed to said housing and extending from said transverse wall structure longitudinally in the opposite direction from said sector, said connector pins also having portions extending through said transverse wall structure toward said sector and with said portions having fixed switch contacts, an actuator arm pivotally mounted on said housing, spring means connecting said sector and said actuator arm in a manner to form a toggle linkage, a movable contact carrried by said sector and engaging said fixed contacts when the sector is toggled to a first position and being separated from said fixed contacts when the sector is toggled to a second position, said sector having a wall spaced from said transverse wall structure and a skirt projecting from the sector wall toward said transverse wall structure, said skirt surrounding said fixed and said movable contacts and being in sliding engagement with said transverse wall structure, said sector thereby cooperating with said transverse wall structure to form substantially an imperforate enclosure for the fixed and movable contacts.
 2. A switch according to claim 1 in which said transverse wall structure includes two adjacent wall sections in surface-to-surface engagement.
 3. A switch according to claim 1 in which said wall structure has a groove running between the fixed contacts.
 4. A switch according to claim 2 in which one of said wall sections is engaged by said skirt, said one wall section and said sector being of a material having a higher resistance to arcing than the other wall section.
 5. A switch according to claim 1 in which said movable contact is an annular element and a projection is integral with said sector for loosely receiving said element.
 6. A switch according to claim 5 in which said projection is oval shaped at the part that is received by said element.
 7. A switch according to claim 1 in which said movable contact has opposed arms for respective engagement with said fixed contacts, and said sector is internally grooved for receiving said movable contact. 